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In theory, it is possible, since when a MIGRATED_ISOLATE page i= s freed, >> __free_one_page() can find its buddy and add the freed page to its bud= dy's >> buddy_list without performing a merge like current code. But it needs = a new >> code path in __add_to_free_list(), since it is not added to the head n= or the >> tail of a free list. > > But what if the whole pageblock gets freed in a single shot (IOW, there= is no buddy to lookup the list for?). You are right. This means when MIGRATE_ISOLATE is removed, the global MIGRATE_ISOLATE free list stays. BTW, looking at struct free_area, its nr_free accounts for free pages in all migratetypes. Either struct fr= ee_area stays the same or more code changes are needed to have isolated free list= + !isolated free list. I will try to figure this out in the follow-up pat= chset. -- Best Regards, Yan, Zi